1. Field of the Invention
The present invention relates to a process for manufacturing a semiconductor device, a semiconductor device, and a high-frequency circuit.
2. Description of the Background Art
Various manufacturing variants for semiconductor components by partial overgrowth of oxide layers with monocrystalline silicon by solid phase epitaxy are described in the Journal of the Electrochemical Society, 138 (1991), No. 12, pp. 3771-3777; Journal of Crystal Growth 98 (1989), pp. 519-530; Applied Physics Letters, 49(7), 1996, pp. 397-399; Applied Physics Letters, 60(1), 1992, pp. 80-81; Applied Physics Letters, 52(20), 1988, pp. 1681-1683; Applied Physics Letters, 43(11), 1983, pp. 1028-1030; Applied Physics Letters, 52(21), 1988, pp. 1788-1790; Applied Physics Letters, 56(6), 1990, pp. 560-562; Applied Physics Letters, 48(12), 1986, pp. 773-775; Applied Physics Letters, 53(26), 1988, pp. 2626-2628; Applied Physics Letters, 49(20), 1986, pp. 1363-1365; Journal of Applied Physics, 64(6), 1988, pp. 3018-3023; Japanese Journal of Applied Physics, 35, 1996, pp. 1605-1610; and the Japanese Journal of Applied Physics, 31, 1992, pp. 1695-1701. Here, an oxide layer is first applied to a silicon wafer. Seed windows where the monocrystalline lattice of the wafer is exposed are opened in the oxide layer. An amorphous silicon layer is then applied and crystallized outwardly from the seed openings.
It is known from U.S. Pat. No. 5,534,716 to crystallize a film layer of silicon in a predetermined direction. In this regard, selective metal atoms are added that have a catalytic action for the crystallization of amorphous silicon. This is used for manufacturing a TFT (Thin Film Transistor) with a high critical frequency or a TFT with a low leak current on the same substrate. It is specified that transition metal impurities lower the nucleation temperature on the silicon below the growth temperature for nuclei.